Tank



FIG. 1 is a front, right-side perspective view of a tank showing my design;

FIG. 2 is a rear, left-side perspective view;

FIG. 3 is a front elevation view;

FIG. 4 is a rear elevation view;

FIG. 5 is a left-side elevation view;

FIG. 6 is a right-side elevation view;

FIG. 7 is a top plan view; and,

FIG. 8 is a bottom plan view.

The broken lines shown in the drawings represent portions of the tank that form no part of the claimed design. 

CLAIM The ornamental design for a tank, as shown and described. 